The purpose of the Biological Studies Core (RC2) facility is to provide a centralized resource for biomarker analyses in support of Duke Pepper OAIC projects to evaluate biomarker profiles as mediators and predictors of function and functional decline. This Core will provide a comprehensive laboratory facility for assays of cellular, molecular, biochemical and metabolomic factors related to aging and functional decline, inflammation and joint tissue metabolism.. The proposed Core Facility will serve in these capacities and will provide biomarker analyses to three large new externally funded studies in human cohorts to validate associations, discovered through the Duke Pepper OAIC in the previous 5 years, of physical function and functional decline with biomarkers, and to expand, enhance and refine knowledge related to these biomarkers as potential mediators and predictors of function. These three cohorts will afford the opportunity to: 1) assess the strength of the prognostic capability of the biomarkers for predicting risk of functional decline or mortality over the subsequent 1-3 years; 2) assess concurrent change in biomarkers and function in a community sample with acquisition of baseline and 24-month longitudinal samples; 3) assess both concurrent change in biomarkers and functional status and the impact of an exercise intervention on biochemical and metabolic markers as well as physical function. The Core Facility will also initially support one Developmental Project to advance the understanding of metabolic function and aging. This project will focus on developing a targeted mass spectroscopic analytic method for acylglycines in urine and will evaluate concurrent change in this new marker and metabolic health and insulin resistance with a clinical trial intervention of glycine supplementation in animals. This Core will also continue to serve as a resource for the training of investigators on principles and methods of biomarker analyses. These biomarker studies are expected to provide further insights into the molecular pathophysiology of aging to inform potential new strategies for intervention and modification of functional decline. The overall approach will continue to be one of a 'Collaboratory' in which multiple excellent clinical studies will contribute subsets of samples for biomarker analyses by the Duke Pepper OAIC Biological Studies Core, and statistical analysis of results by the Duke Pepper OAIC Analysis Core, to address, jointly and severally, the overarching Duke Pepper OAIC theme of exploring approaches to understand and modify multiple pathways of functional decline, and to translate noteworthy findings into disseminated knowledge through publications and advances in health.